


From Crown Prince to King's Breeder

by omegadeanlovesalphacas



Category: Supernatural
Genre: Alpha Castiel, Alpha Dean forcibly changed into an omega, Alpha/Beta/Omega Dynamics, Alpha/Omega, Bondage, Bottom Dean, Breeder Dean, Breeding, Butt Plugs, Claiming, Humiliation, Knotting, Lactation, M/M, Mpreg, Omega Dean, Oral Knotting, Public Sex, Punishment, Pups Watching, Slave Dean, Top Castiel
Language: English
Status: In-Progress
Published: 2016-11-14
Updated: 2016-11-14
Packaged: 2018-08-31 01:05:15
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 2
Words: 2,524
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8556700
Author URL: https://archiveofourown.org/users/omegadeanlovesalphacas/pseuds/omegadeanlovesalphacas
Summary: Alpha King Castiel has captured Alpha Prince Dean. If Castiel can force Dean's body to change into an omega, he can claim the prince as his breeder and rightfully claim Dean's kingdom as well.





	1. Chapter 1

**Author's Note:**

> Warning! This is an Alpha/omega kink prompt fill. Expect more porn than plot, and lots of power imbalance between Cas and Dean. Mind the warnings and kinks in the tags.
> 
> Anonymous said to omegadeanlovesalphacas:  
> Captured Alpha!Prince!Dean Dean is forcibly turned into an Omega by his captor, Alpha!King!Castiel, by fucking him full of Alpha! cum. He breeds Dean into submission and ends with a pregnant!Dean sucking Cas off while he sits on his conquered throne.
> 
> Filled on Tumblr, January 2016

Dean squirmed and tugged at the thick leather that strapped him to the breeding bench. It didn’t budge. He cried out into the gag that filled his mouth, but nobody answered. He shivered when he felt the strong hand of King Castiel run down his backside, until his finger found the tight ring of Dean’s ass.

“Prep him,” Castiel ordered.

Dean’s eyes widened as the King moved around to his face, and he could hear a servant setting out supplies behind him. Castiel ran his hand through Dean’s hair, just as he suddenly felt the pressure of a slick finger pushing inside him. He cried out, but it was muffled again, and he couldn’t do anything to stop the hand that was violating him.

“You’re going to be mine,” Castiel said calmly. “Once you’ve bore my heir, no one will be able to deny my claim to your father’s kingdom.”

Dean shuddered. This wasn’t how he had expected the war to end. He had expected victory, or at least the glorious death of an honorable Alpha prince. He hadn’t expected to be captured and given to the enemy King. And now this.

The fingers pulled free of Dean’s now slick hole, and he only had a moment to feel relief before the King moved around him again, returning to his now prepared backside. Dean’s eyes closed tight as he heard the rustle of Castiel’s trousers, then snapped open again in shock when the King’s thick cock suddenly slammed inside him without warning.

Castiel was claiming him, each hard and fast thrust making that perfectly clear. Dean cried and moaned at the brutal treatment, but it didn’t last long. He was very quickly being split open by the Alpha’s huge knot, and Dean could only whimper as the King finally stilled and started to pump him full of seed.

Dean groaned as he was filled by the Alpha, and he was shocked to feel his own cock start to swell in response. It was so wrong, unnatural, this couldn’t actually be happening.

Castiel chuckled. “That’s the first sign that your transformation will take,” he said, reaching around to toy with Dean’s heavy cock. “It will take many more knots before it is complete.”

Dean squirmed in his tight bonds, trying to ignore the way his skin tingled as the King ran his hands across his backside. The discomfort was fading and he realized his body was stretching open and accepting the invasion of the Alpha’s knot. He slumped in dejection, realizing he could do nothing but wait.

Castiel’s knot eventually started to shrink, and the Alpha finally pulled free. Dean sighed in relief, then grunted when a thick plug was shoved into his ass, replacing the fullness of the knot and keeping the King’s seed inside him.

“Rest. I’ll be back soon,” Castiel said, running a hand through Dean’s hair. Then he left without a word.

Dean didn’t have to wait long. He wasn’t sure how much time had passed, but he was just starting to wonder if he would be able to sleep in his current position when the King returned. This time he was given no warning or further prep, Castiel simply walked up behind him, removed the plug and thrust his hard cock back into Dean’s tender hole.

Dean whimpered as the King fucked him again. It was just as hard and fast, only this time he was startled to feel his body responding to it. Tingling pleasure was building inside him with each thrust, until he realized he was moaning into his gag. It wasn’t enough to make him come, but it was more than enough to humiliate him.

It wasn’t long before the King’s knot filled him again, pumping him full of more seed. “Your transformation is starting,” he said, running his hand up and down Dean’s back. “Soon your body will start to produce slick, and then your belly will start getting ready to take my pups.” His hand moved lower and groped Dean’s heavy balls and thick cock. “These will soon start to shrink.”

Dean groaned and closed his eyes, not wanting to think about that. But he was suddenly feeling warm and woozy. His mind was swimming with exhaustion and a buzzing need. He whimpered when he felt something in his belly cramp and then rumble, and he realized the King was right, he really was changing.

This time when the King replaced his knot with the plug Dean was quick to slip into a light sleep.

Dean wasn’t sure how much time passed after that. He would wake when he felt the plug pulled free of his body, and he couldn’t stop the way his back arched to meet the Alpha’s touch. He moaned wantonly when he was fucked. Each time it was more pleasurable than the last, but he never seemed quite able to come. The Alpha continued to knot him and fill him, and Dean could feel his belly swelling with it, growing almost painfully full.

Dean was moaning through another hard fucking when it finally happened. The rumbling in his belly suddenly stopped, and he whimpered when he felt his whole body shudder in a strange sort of release. The next thing he noticed was the pressure of the Alpha’s come suddenly giving way inside him, and he cried out in pleasure and he realized it was the King’s seed flooding his new omega womb.

“Finally,” Castiel growled, hips slapping against Dean’s ass as he fucked him. “You’re an omega now, I can smell it. Time to breed you full of pups.”

Dean gasped when he felt the Alpha unbuckling the gag, and he moaned louder as it finally fell from his mouth. “Alpha,” he groaned.

“Beg,” Castiel ordered, thrusting harder as his knot filled again. “Beg like a good little omega. Tell me you’re mine, show me you want to be bred up like a good bitch.”

“Please,” Dean gasped, blindly desperate to please the Alpha. “Please Alpha, fill me with pups, I’ll be a good omega. Your omega!”

Castiel growled and slammed into Dean. “Now come on my knot like a good omega,” he ordered, and slammed his knot into place as he came with a long groan.

Dean screamed with pleasure as his orgasm crashed through him, his whole body spasming as he clenched hard around his new Alpha’s knot. His orgasm seemed to go on forever, and he could only slump with exhaustion when it finally came to an end.

Castiel let out a pleased little growl and leaned down over Dean, his teeth finally sinking into the skin on Dean’s neck, claiming the new omega as his own.

* * *

Dean hummed with pleasure as he sucked eagerly on his Alpha’s thick cock. Pleasing his mate always made him feel content. He didn’t even spare a thought for how he looked.

He was naked, but for the gold collar speckled with beautiful gem stones, and his belly was heavy with the King’s pups. He knelt on his pillow, which sat in it’s rightful spot in front of his Alpha’s thrown. The King loved to show Dean off.

Castiel had been right, Dean’s body had changed dramatically. His cock and balls were much smaller now, as is common for an omega. He was losing muscle mass too, becoming much more slim and petite.

Dean moaned as Castiel’s knot swelled and filled his mouth, and when the Alpha finally came he settled in on his pillow, content to gently suckle the cock that filled his throat until the knot went down. He could feel his stomach start to fill with his mate’s seed, and he squirmed a little on the plug in his ass, which held an earlier breeding session inside him.

Castiel ran his hand lovingly through Dean’s hair, and the omega looked up at the King with adoring eyes. “That’s my good little omega,” Castiel said with a content smile.


	2. Chapter 2

Castiel loved holding court. Nothing pleased him more than letting everyone look upon his beautiful, perfectly submissive omega, as well as the heirs that cemented his kingdom and his progeny.

Walking into the thrown room he grinned widely at the sight of his omega and his pups waiting for him. Dean sat on his pillow, heavily pregnant and holding a nursing nearly nine month old pup. Their three 18 month old pups sat on the floor nearby playing with their blocks, and the two year old twin boys stood nearby, chatting with the two nannies who doubled as Dean’s keepers.

The pups and their nannies were all dressed in the finest clothes. Dean was naked, but for his gem studded gold collar.

The twins noticed Castiel coming and they ran to him, faces split with wide grins. “Papa!” they called out, throwing themselves in his arms.

Castiel laughed happily. “How are my two favorite boys?” he asked, lifting them both eagerly.

They both started chattering at once, telling him the stories of their morning, simple little things becoming grand adventures in the two year olds’ minds. James suddenly declared that he was hungry, so Castiel set them both down. James scampered over to Dean, and without asking he simply climbed on Dean’s lap and started to suckle on Dean’s small breast.

Jonathan smiled up at Castiel. “Omega breeder can’t say no to us, ‘cause he’s just for making pups and milk. He’s submis’ to us,” he said proudly, not quite mastering ‘submissive’ just yet.

Castiel smiled indulgently down at his son. “Yes that’s right, his job is to make pups for papa and keep them fed.” His two eldest sons had been learning about omegas and the difference between an omega of good station and an omega breeder like their mother.

* * *

Dean blushed when he heard the two year old assert his position of power over him, but he said nothing, just sat submissively and continued to nurse the two pups. It was embarrassing to be reminded of his low station by his own toddler, but that was the life of a royal breeder. The eldest pups were almost entirely on solid foods, but they still liked to nurse from time to time, even more so now that they were testing their dominance over Dean.

Most of the time Dean was very accustomed to his life, and very few things could break him out of his happy omega haze. But today he was a little more mindful of everything, of his nudity, the pups hanging from his little breasts, of the thick plug that held his Alpha’s seed in his ass. The thick collar that claimed his neck.

Castiel strode toward them, and Dean made sure to duck his face submissively. The Alpha took his seat on the thrown, spreading his legs so that Dean sat between him against the front of the thrown. He sat forward and leaned over Dean, taking his chin in hand and forcing him to look up at him. Dean melted under the hard gaze of his Alpha, losing himself again in submission to his powerful mate.

“Don’t think I can’t tell exactly what you’re thinking,” Castiel said, eyes narrowing dangerously. “Tell me what you are,” he ordered.

Dean blushed faintly, but quickly obeyed. “I’m your omega breeder. Only good for being fucked, and making pups and milk.” The two pups suckling hard on his little breasts seemed to drive the point home.

Castiel smiled. “That’s right.” His hand went down to rub Dean’s swollen belly. “Those pups are going to pop any day now. Can’t wait to fuck you full of a new ones.”

“Yes, Alpha,” Dean said, ducking his eyes. He was quite used to being pregnant by now, the Alpha had made it very clear he intended to keep Dean well bred until he was all used up.

Little James pulled off Dean’s teat with a smack, and Jonathan shouldered in to take his place, latching on and starting to suckle. It seemed that no matter how long the pups nursed, Dean never ran dry.

Castiel smiled and started to unbuckled his pants. Without being told Dean opened his mouth and rested his head back against Castiel’s strong thigh, then took the Alpha’s thick cock in his mouth. He relaxed his mouth, simply holding the half hard cock and keeping it warm and wet.

This was how Castiel always displayed Dean to the court. Naked, mouth full of the king’s cock, pups hanging off his tits, and belly bred full. No one ever dared challenge Castiel’s right to Dean or the land he took with the omega.

Dean was aware enough of his humiliation to blush red when the doors opened and the lords and ladies of the court filed in. But today, like most days, he couldn’t really remember any life before this to understand why it should be so embarrassing. He was a breeder, this was what he was good for, of that he was certain.

The people of the court barely spared him a glance, so used to seeing him on display. Castiel absently stroked Dean’s hair while he conducted business, while the pups continued to suckle and use Dean as they wished. Dean continued to hold the kings cock in his mouth, and he could feel it steadily growing harder, filling his mouth and pushing into his throat.

Eventually Castiel patted Dean on the cheek and ordered, “Suck.”

Dean obediently started to suck on the cock in his mouth, forgetting about the watching crowd as he slipped lower into the submissive mindlessness that always came from pleasing his Alpha. The nannies took the sleeping pup from his arms, and he felt two of the 18 month olds climb onto his lap and start to nurse on him. Even at their young age they understood they could take from Dean as they wished.

Dean obediently sucked until the king’s knot swelled in his mouth, the thick cock filling the back of his throat when Castiel finally came, ropes of come shooting down Dean’s throat. Dean could only suckle and swallow, the knot firmly tied behind his teeth, all while his pups still greedily suckled on him.

Dean sat like that for a few minutes, until his pups were full and pulled away, going back to their toys. He thought he had earned a reprieve, but Castiel stroked his hair and turned to the nannies. “My breeder needs to be milked,” he said with a smile.

Dean’s face burned red as he continued to suckle the king’s knot, this was not a humiliation he usually had to suffer in front of the court. Clearly Castiel was punishing him for his stray thoughts earlier.

The nannies just nodded and left for a moment, returning quickly with two breast pumps. They turned Dean so that everyone could see as they attached the suction cups to each of Dean’s little breasts and then turned on the small motor. Dean whimpered as the little machine sucked hard on his breasts, drawing milk from them.

Castiel just smiled and pet Dean’s head as the omega continued to suckle his knot. “Such a good little breeder.”

**Author's Note:**

> Thanks for reading! Comments are love! <3
> 
> Visit me on Tumblr: [omegadeanlovesalphacas.tumblr.com/mobilemenu.](http://omegadeanlovesalphacas.tumblr.com/mobilemenu)


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